Ubuntu: Upgrade Ubuntu 11.10 to 12.04LTS [duplicate]

Question:

After installing and checking few times for packages that are not in Ubuntu 11.10. I decides to upgrade to version 12.04LTS. But I can`t find an "Upgrade" button. And of course the sentence 'New Ubuntu release 12.04LTS is available'. What is a wrong here? How can I upgrade?

Solution:1

You will not see an upgrade button unless you bring up Update Manager. Below are different ways that can help you in your process.